A conventional circuit breaker, shown in FIG. 1 of the attached drawings, includes a body 100 and first and second terminals 200, 300 connected to the body. The terminals 200, 300 extend through two slots defined in an underside of the body 100. A bi-metallic plate 400 is removed in the body 100 and one end of the bi-metallic plate 400 is fixed to the first terminal 200. A first contact point 401 is connected to a second end of the bi-metallic plate 400 so as to be in contact with a second contact point 301 on the second terminal 300 so as to form a circuit. A neck member 101 is fixed to the body 100 and an end of a button 500 extends through the neck member 101 and a spring 501 is biased between an end of the button 500 and an inside of the body 100. The button 500 is movably extended through the neck member 101 and an inside of the button 500 is engaged with an inner periphery of the neck member 101 so that the button 500 is not disengaged from the neck member 101. When current overflow, the bi-metallic plate 400 is deformed so that the first contact point 401 moves away from the second contact point 301 to cut the circuit off.
Nevertheless, the neck member 101 and the first part 102 of the body 100 have to be manufactured individually by two different molds which increase the cost. Besides, it takes a lot of time to assemble the separated parts. Furthermore, when assembling the button 500, the neck member 101 and the spring 501 into the body 100, all the parts are not well settled in position so that the assemblers have to carefully position these parts during assembling. When one of these parts is not positioned at desired position during assembling, the assembling process has to be re-assembled all over again.
Therefore, it is desired to develop a new and simple structure for the circuit breaker that reduces the manufacturing cost and time required to assemble the breaker.